If "Where do you want to forward that one to?" is correct, then "Where do you want that one forwarded?" should be as well.
No, these are not equivalent as the actor in both cases is not necessarily the same person.
I wrote: "Where would you like to forward it" and it is wrong. I find myself doing this often where I soften "what do you want" with "what would you like" is there an equivalent softening in german that is used?
"Wohin möchtest du?" is a bit softer than "Wohin willst du?". Note that the subjunctive is derived from the verb 'mögen', not 'wollen'.